Enhancing the performance of quantum battery by squeezing reservoir engineering

Reservoir engineering has been widely used in various quantum technologies. Based on a cavity-QED (quantum electrodynamics) model, we propose a potentially practical scheme using squeezed-vacuum reservoir engineering to optimize the performance of a quantum battery (QB) located inside a cavity driven by a broadband squeezed laser, which acts as a squeezed-vacuum reservoir. Using the reduced master equation of the QB obtained via the adiabatic elimination method, we focus on the QB’s charging dynamics under tunable squeezed reservoirs governed by parametrically controlled squeezing parameters, which dictate the efficiency of energy transfer and the extractable work (ergotropy) of the QB. We show that increasing the squeezing strength improves the charging rate and enables rapid energy transfer, whereas the steady-state energy of the QB saturates at specific values of the squeezing parameter. Notably, the ergotropy of the QB reaches its maximum at a critical squeezing strength and does not scale monotonically with the squeezing strength. This nonmonotonic behavior underscores the existence of optimal parameter regimes, through which the performance of the QB can be significantly enhanced.